radicalism

Here are a few starting points:

Books:
Nestor Makhno--anarchy's cossack: the struggle for free Soviets in the Ukraine 1917-1921
Russia's lost reformation: peasants, millennialism, and radical sects in Southern Russia and Ukraine, 1830-1917
Radical socialism in Czechoslovakia: Bohumír Šmeral, the Czech road to socialism and the origins of the Czechoslovak Communist Party, 1917-1921

Articles:
NATION VS HUMANKIND: THE PROBLEM OF NATIONAL IDENTITY IN GEORGIAN THOUGHT. Tevzadze, David.; History of European Ideas 1994 19(1-3): 431-436
THE EVOLUTION OF AN ANARCHIST: AUTOBIOGRAPHICAL STATEMENT BY VARLAAM TCHERKESOFF, 1846-1925. Startt, James D.; Biography: An Interdisciplinary Quarterly 1987 10(2): 142-150
MARXISM, NATIONALISM AND THE ARMENIAN LABOR MOVEMENT IN TRANSCAUCASIA, 1890-1908. Suny, Ronald Grigor.; Armenian Review 1980 33(1): 30-47